Method and apparatus for activating and accessing remote meter interface devices

• US 5,726,646 A
• Filed: 01/22/1996
• Issued: 03/10/1998
• Est. Priority Date: 04/04/1994
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Bane, Ronald L., Barlow, James M.
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): HILL, ANDREW M
• Application Number:
  US08/589,718
• Time in Patent Office: 778 Days
• Field of Search: 340/870.02, 340/870.03, 340/870.11, 340/505, 340/825.44, 340/825.54, 340/825.47, 455/38.2, 455/38.3, 455/56.1, 455/343
• US Class Current: 340/870.03
• CPC Class Codes: G08C 17/02 using a radio link

Abstract

A remote meter reading system (10) includes a group of meter interface units operable in an inactive state and periodically activated to monitor a communication channel for activity. Each meter interface unit (12) is responsive to communication signals from a meter reading device (15). The meter reading device (15) initiates communication with a first meter interface unit (12) selected from the group. The meter reading device (15) transmits to the first meter interface unit, a first message including a request for data. The meter reading device (15) then receives transmissions from the first meter interface unit (12) which are governed by a first transmission rule. The meter reading device (15) determines when at least a second meter interface unit (12) is operating in an active state, and transmits to the first meter interface unit (12), a second message including a specifier for a second transmission rule.

Claims

1. In a remote meter reading system including a group of meter interface units wherein each meter interface unit is operable in either an active or an inactive state to reduce power consumption, wherein each meter interface unit is periodically activated to monitor a communication channel for channel activity, and is responsive to communication signals from a meter reading device, a method of activating and accessing a group of meters, comprising the steps of:

at the meter reading device;

initiating communication with a first meter interface unit selected from among the group of meter interface units;

transmitting on the communication channel a first message to the first meter interface unit;

receiving transmissions from the first meter interface unit, the transmissions being governed by a first transmission rule;

transmitting, to the first meter interface unit, a second message indicating a second transmission rule when at least a second meter interface unit is operating in an active state.

2. The method of claim 1, wherein the step of initiating communication with a first meter interface unit selected from among the group of meter interface units, includes the step of:

transmitting a wake-up request including a unit identifier identifying the first meter interface unit.

3. The method of claim 1, wherein the step of transmitting on the communication channel a first message to the first meter interface unit, includes the step of:

transmitting a request for data.

4. The method of claim 1, wherein the step of transmitting on the communication channel a first message to the first meter interface unit, includes the step of:

transmitting a specifier for a first transmission rule as part of the first message.

5. The method of claim 4, wherein the step of transmitting a specifier for a first transmission rule as part of the first message, includes the step of:

transmitting a size limit for a continuous stream of data in a transmission.

6. The method of claim 4, wherein the step of transmitting a specifier for a first transmission rule as part of the first message, includes the step of:

transmitting a time limit for a continuous channel transmission.

7. The method of claim 6, wherein the step of transmitting a specifier for a first transmission rule as part of the first message, further includes the step of:

transmitting a minimum value for a delay period between successive channel transmissions as part of the first transmission rule.

8. The method of claim 1, further comprising the steps of:

at the first meter interface unit;

dividing data responsive to the first message from the meter reading device into first and second data segments; and

transmitting the first and second data segments in successive transmissions to the meter reading device.

9. The method of claim 8, wherein the step of dividing data responsive to the first message from the meter reading device into first and second data segments, comprises the step of:

determining a data segmentation criteria based at least in part on a transmission rule specified in a transmission from the meter reading device.

10. The method of claim 8, wherein the step of dividing data responsive to the first message from the meter reading device into first and second data segments, comprises the step of:

determining a data segmentation criteria from a transmission rule stored in data storage area accessible by the first meter interface unit.

11. The method of claim 1, wherein the step of receiving transmissions from the first meter interface unit, the transmissions being governed by a first transmission rule, comprises the steps of:

at the meter reading device;

receiving data segments in successive transmissions from the first meter interface unit in compliance with the first transmission rule; and

transmitting a message after each successive transmission from the first meter interface unit.

12. The method of claim 11, wherein the step of transmitting a message after each successive transmission from the first meter interface unit, includes the step of:

at the meter reading device, transmitting a wake-up request to at least the second meter interface unit.

13. The method of claim 11, wherein the step of transmitting, to the first meter interface unit, a second message indicating a second transmission rule when at least the second meter interface unit is operating in an active state, includes the step of:

specifying a transmission rule indicating an absence of a size limitation imposed by the meter reading device for a continuous stream of data.

14. The method of claim 1, further comprising the step of:

at the meter reading device, transmitting the first transmission rule when transmitting to the first meter interface unit until at least the second meter interface unit is operating in an active state.

15. The method of claim 1, wherein the step of transmitting, to the first meter interface unit, a second message indicating a second transmission rule when at least the second meter interface unit is operating in an active state, includes the step of:

specifying a transmission rule indicating an absence of constraints imposed by the meter reading device on continuous channel transmissions.

16. In a remote meter reading system including a group of meter interface units wherein each meter interface unit is operable in either an active or an inactive state to reduce power consumption, wherein each meter interface unit is periodically activated to monitor a communication channel for channel activity, and is responsive to communication signals from a meter reading device, a method of accessing a group of meters, comprising the steps of:

at the meter reading device;

initiating communication with a first meter interface unit selected from among the group of meter interface units;

transmitting to the first meter interface unit, a first message on the communication channel the first message including a request for data and a specifier for a first transmission rule, the first transmission rule indicating a limit for continuous channel transmissions;

at the first meter interface unit;

dividing data responsive to the request for data from the meter reading device into at least first and second data segments;

transmitting the first and second data segments in successive transmissions to the meter reading device, the transmissions being governed by the first transmission rule;

at the meter reading device;

transmitting a message after each successive transmission from the first meter interface unit, the message including a wake-up request to at least a second meter interface unit;

transmitting to the first meter interface unit a second message indicating a second transmission rule when at least the second meter interface unit is operating in an active state, the second transmission rule indicating an absence of constraints on channel transmissions.

17. A meter reading device for communicating with first and second meter interface units, the meter interface units being operable between active state and an inactive state to reduce power consumption, the meter reading device comprising:

a controller, an electrically coupled memory portion, an electrically coupled transmitter, an electrically coupled receiver, and an electrically coupled antenna cooperating to transmit to the first meter interface unit a first message including a request for data, and to receive successive transmissions from the first meter interface transmitted under a first transmission rule, and to transmit a specifier for a second transmission rule to the first meter interface unit when the second meter interface unit is operating in an active state.

18. A remote meter reading system, comprising:

a plurality of remotely accessible meter interface units wherein;

each meter interface unit is operable in an inactive state to reduce power consumption, and is periodically operable in an activated state to monitor a communication channel for channel activity, each meter interface unit being responsive to a wake-up request for operating in an activated state for an extended time period, and being responsive to requests for data; and

a meter reading device, comprising;

means for initiating communication with a first meter interface unit selected from among the group of meter interface units;

means for transmitting to the first meter interface unit, a first message on the communication channel including a request for data;

means for receiving transmissions from the first meter interface unit, the transmissions being governed by a first transmission rule;

means for transmitting to the first meter interface unit, a second message including an indication for a second transmission rule when at least the second meter interface unit is operating in an active state.

19. A remote meter reading system, comprising:

first and second meter interface units wherein;

each meter interface unit is operable in an inactive state to reduce power consumption, and is periodically operable in an activated state to monitor a communication channel for channel activity, each meter interface unit being responsive to a wake-up request for operating in an activated state for an extended time period, and being responsive with successive transmissions to requests for data; and

a meter reading device, comprising;

a controller, an electrically coupled memory portion, an electrically coupled transmitter, an electrically coupled receiver, and an electrically coupled antenna cooperating to transmit to the first meter interface unit a first message including a request for data, and to receive successive transmissions from the first meter interface transmitted under a first transmission rule, and to transmit a specifier for a second transmission rule to the first meter interface unit when the second meter interface trait is operating in an active state.